Chronic inflammatory disease is believed to pose a tremendous medical burden in the developed world, not only in terms of patient suffering but also in the cost of treatment and loss of worker productivity. The more common inflammatory diseases include rheumatoid arthritis, inflammatory bowel disease, atherosclerosis, chronic obstructive pulmonary disease and psoriasis. Although each disease has unique aspects regarding the affected tissues and the clinical symptoms, they all share some common biological mechanisms for the establishment and maintenance of the disease state. Endothelial cells are of critical importance in detecting the earliest signals broadcast from the damaged tissue and amplifying this signal by attracting and immobilizing lymphocytes, allowing infiltration of the tissue to produce a full-blown inflammatory response. A critical event in this process is cell surface expression of E-selectin, which is essential for lymphocyte adherence. The goal of the proposed project is to use a cell based assay to screen for compounds which block activation of the endothelial cell. Primary human cells (HUVEC) will be stimulated by cytokine and the activation monitored by cell surface expression of the adhesion molecule E-selectin. A cell surface E-selectin assay for automated image analysis by the InCell Analyzer 3000 imaging system was successfully implemented to stage III (Analysis/result acquisition). The assay can generate data with high confidence and a Z' factor of 0.77. We have also shown that the assay a powerful tool to screen for bioactive compounds. [unreadable] [unreadable]